1. Field of the Invention
The invention relates to a method and apparatus for the representation of characters.
2. Description of the Prior Art
It is generally known to represent characters, i.e , their strokes, in office typewriters, teleprinters or data printers by the use of a print element designed as a matrix print element. Given employment of a print element which is moved in the line direction relative to a recording medium during the printing operation, it is standard to arrange a plurality of print elements adjacent to and above one another. During the motion of the printing element, different print elements are driven controlled by data words stored in a character generator and the characters are printed on the recording medium in a prescribed dot matrix. Wire matrix printing elements can be employed as printing elements, printing needles being selectively actuated therein by means of magnetic elements. Ink printing elements can also be provided as printing elements, ink droplets being electively ejected from nozzles given these.
Those characters whose strokes, such as the lower case letters "a", "c" only exhibit a central area and no ascenders and descenders are printed by a first portion of adjacent printing elements. Those characters whose strokes exhibit a central area and at least one ascender such as, for example, upper case letters and some of the lower case letters such as "d" and "f", are printed by the first and second part of the printing elements. Finally, those characters whose strokes exhibit a central area and a descender, for example, the lower case letter "g", "p", are printed by the first and third part of the printing elements. It is also possible to represent capitalized printing with the assistance of all printing elements, this consisting of upper case letters which are printed by all printing elements.
In case even larger characters are desired, it is conceivable to print an upper part of the characters during a first motion of the print element in a line direction, to then shift the recording medium perpendicularly relative to the line direction by the height of said first part and to subsequently print the second part of the characters during a second motion of the print element in the line direction. The directions of the first and second line direction motions of the print element can coincide or can proceed in opposite directions for instance, left or right. In the former instance, a return of the print element into its initial position is carried out after printing the first part of the characters and the second motion is subsequently carried out; whereas, in the second instance, the print of the second part of the characters ensues during the return of the print element.
Such a method has the disadvantage that an offset can occur within the characters as a result of impressions in the forward feed of the recording medium and the legibility of the individual characters is thereby deteriorated.